Revisited 68 Chevy

Tom in Mo. · Aug 29, 2016

I've been staring at it a day now and I believe you guys are correct about it having the 307 engine but I can't read the numbers off the block. The glove box sticker says it has the Turbo Hydramatic option too. It does have a long oil fill tube right up off the intake manifold like the 283's.
The inside of the fuel tank behind the seat is layered with rust so I may try to find a replacement. The old gas that I drained out was thick, dark brown and stunk. Looks like she will run again.

jimg.allentown · Aug 29, 2016

In that vintage, it would have the Turbo Hydramatic 400. The THM 350 didn't come out until 1969. Be glad if you don't have a power glide. They were 2 speeds, and the high clutch was famous for burning out. They worked OK for a 2-speed, but didn't last long.

old · Aug 29, 2016

I have parts and pieces of 3 1969 Chev pick up and a 1972 GMC on the place here at the Lake of the Ozarks. I have wanted to do a mini semi made form a 1969 Chev 3/4 ton but have never gotten around to it yet. I want to do a tandem rear drive in it and a twin stick

47fivewindow · Aug 29, 2016

Slip n slide....Power Glide!

huntingreen2day2 · Aug 29, 2016

Yes but some of them you could push start and they were easy to work on.

Dean · Aug 30, 2016

Assuming that you are speaking of a pick up truck, Chevrolet use the 307 and the 327 engines in light trucks in 1968.

They also used the powerglide and TH 400 transmissions. Both were ultra reliable.

Dean

gab · Aug 30, 2016

My first car was a nice 64 Impala 2 dr. with a power glide, also had a 64 Super sport Impala with one and a 59 impala and 61 Belair wagon, 59 and 61 were huntin/fishing/beer drinking utility type screwing around units but never tore up a power glide.

ditchwitch · Aug 30, 2016

Tom look at the pan on the transmission if its about 3 1/2 inches deep its a 400 turbo if the
transmission pan looks like just a couple inches deep its a 350 turbo. I have never saw a 400 turbo
in a 68 chevy 1/2 ton truck factory but have seen plenty of 327 motors with 350 turbo transmissions
. I also have a question about Missouri and hunting do you have a email i can ask a couple
questions?? I have booked a hunting trip to Missouri for a big deer (hopefully) for the November 5th
through the 10th

Leroy · Aug 30, 2016

My truck was a 70 model but carried the GMC tag and had the 307. I don't know if all were like mine or not as mine seemed to have non standard parts that were hard or impossible to get. The present owner found out that the carb took Dodge parts that trying everything eles could not be found so when I had it they changed everything from the intack over for parts from a 350. My truck I think was part of an expermint that got away and was not supposed to as it was service truck for a Cadillac dealer that went bust and that is when the local small dealer got it and this was back in 76. What better way to try something new than in their own service departments to see how things worked. Has not been repaired yet after fire started 10? years ago when battery was put in after setting a while and burnt all the wiring harness. I don't know how close the 68 Chevy and GMC were in using the same parts but the trucks looked same except for grill.

Tramway Guy · Aug 30, 2016

My friend had a Chevy about that vintage with a 307. He
changed it out with a 283 and was much happier with it.

Ron-MO · Aug 30, 2016

I did not read all the comments from previous post, but 283 was dropped in favor of 307 in 68. I had a 67 as did my dad, and while standard engine was the 6, the 307 was pretty common. Unless of course the
engine was swapped out. In 67 the Turbo Hydramatic 3 speed was a TH400 as they did not put the TH350 in until 68, so you likely have the TH350 trans. The 67 I had was a factory 327, with TH400. My engine
had been swapped to a Corvette 327, and was quite a runner. I did a lot of street racing with that old truck in the day, and that truck was hard to beat when it was running right and up until I hurt the
engine and replaced. It was never the same truck after that, but that TH400 trans was bulletproof. I'd love to find a 67-72 in decent original shape like that.

Ron-MO · Aug 30, 2016

Turbo Hydramatic 3 speed with a 307 would have had the TH350 in 68. That was first year for the TH350. They did still put the TH400 in the big block pickups in 68 such as the 396. But not nearly as many of those built.

Dune Country · Aug 30, 2016

Just tore down a '72 307.
Two of the cylinders had "blemishes" or off color spots.
Took it to a machine shop to be bored and the machinist saw those spots and got a small ball peen and tapped the spots, went right thru, crystallized.
Turns out that GM fudged on the nickle in the 307 casting.

Dean · Aug 30, 2016

I sold my 1968 GMC 2500 series, bought new by my Father when he retired from GM, about 5 years ago after hurricane Ike collapsed my barn onto it.

It came from the factory with a 327 4V, TH-400 transmission, 456 posi-traction axle, AC, etc.

Dean

Ron-MO · Aug 30, 2016

That would have been correct. The key there is it was 3/4 ton so a heavy duty trans, and rear axle. 3/4 ton would have had the TH400 where the 1/2 ton would come with TH350 trans in 68. 68 was first year for TH350 in 1/2 ton pickup.

rustyfarmall · Aug 30, 2016

If I remember correctly, the 307 was Chevy's attempt to conform to new EPA regulations. 1968 was the beginning of the emmisions thing, and new vehicles had to perform satisfactorily on lower octane gasoline. This meant that compression ratios had to be reduced to prevent pinging and knocking. The tried and true 283 c.i. just couldn't deliver with those reduced compression ratios, so the 307 was developed. Had to increase the bore to make up for the lower performance of the reduced compression. Did it work? Well, the EPA was happy, but at the same time a well tuned 283 could easily run circles around the 307 and get better gas mileage while doing it.

bigbob1939 · Aug 30, 2016

The 307 was a 283 block with a 1962---1967 327 crank. Not near the engine the
283 was.

Dean · Aug 30, 2016

Bingo.

Dean

Ron-MO · Aug 30, 2016

Dean, I agree. I loved my 67 C10 with 327 (even though it was not original engine, and the vette engine made it even better). Had the TH400, PS, PB, Air, CST package, speed warning indicator (kind of odd), wood bed floor, and I cannot recall what other options, but the list in glove box was on both sides and had nearly every option available that year - but sadly no posi in it. Was the right color - Red though. As much as I liked that truck, I think they continued to improve them with better power steering, and additional goodies right up to 72. I was looking for a 67-72 C10 when I ran into the 70 F100 Ford Ranger I have now. But don't hold that against me just yet. Never owned a Ford pickup until this one, and always owned a Chevrolet pickup since I was 16 and still have one, albeit a 2011. Really the reason I bought the F100 was that I knew it when it was new, was a 1 owner truck, and it is all there, although it will take a good bit of work to put it back on the road. But the 67-72 Chev are arguably the best looking and most reliable truck IMHO. Who knows, I may get the F100 going, sell and still find what I was looking for, but those trucks are hard to find in MO unless they are either butchered, missing most of the parts or rotted away from salt. His blue 68 is nice for a MO truck.

Tom in Mo. · Aug 30, 2016

An update. I didn't lay in the dirt to look at the tranny but the glove box says turbo hydramatic. Small block so prolly a TH350.
The truck has 123208. miles on it and according to an ATK remanufactured engine book in the glove box, it was repowered with a remanufactured 350 in dc08. The flat with the engine code is machined off, typical of a rebuild. Not the original engine and don't know what it replaced. Fun project.
And it is tractor related because it's parked next to a JD1020.

Mark - IN. · Aug 30, 2016

307. A couple of things happened in '68 for Chevy. The 283 was stroked up to a 307. The paper insert oil filter was replaced with a spin on canister. '68 was the last year for a manual in a full sized and I had one, 427 Muncie M22 Impala. In '67 though, Chevy took a 283 crank shaft and stuck it in a 327 and it became a 302. In '69 Chevy came out with the 350 for the Corvette, 327 was still used in all else until '70. In '70 the 396 was bored .030 over and still called a 396, but it was a 402. In '70 the 427 retained its bore, but was stroked up from 3.76" to 4.0" and became the 454. In '70 was the 400 small block that could be stroked down to 373", bored .030 over to a 378" killer that when revved up and clutch dumped and gas pedal hammered would about break the seat loose and flip it and the driver into the trunk as the car launched. My buddy, Rod replaced the 350 in his '70 Z28 with one of those.

Those were some great years, looking back on them. Thanks for the memories.

Mark

Mark - IN. · Aug 30, 2016

...You'll appreciate this.
Farm Truck

Revisited 68 Chevy

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